Water collection system

ABSTRACT

A water collection system blocks down-pipes to collect water from a roof. A down-pipe ( 27 ) is located adjacent a rain water diversion unit ( 31 ). The unit comprises a box ( 36 ) with the down-pipe ( 27 ) fitted to an opening ( 37 ) in bottom ( 38 ) of the box ( 36 ). The gutter ( 14 ) has two side-by-side openings ( 39  and  40 ), the opening ( 40 ) has an overflow in the form of upstanding wall ( 41 ) while the opening ( 39 ) has a valve plate ( 42 ) hinged to the front edge at ( 43 ). A pneumatic actuator ( 44 ) is used to move the valve plate ( 42 ) to the closed position. When the valve is closed, the opening ( 40 ) and the upstanding wall ( 41 ) serve as an overflow back to the stormwater via the box ( 36 ). The tank pipe ( 17 ) also has an opening ( 45 ) with an upstanding wall ( 46 ) which has its upper edge ( 47 ) set lower than the upper edge ( 48 ) of the wall ( 41 ) of the overflow. All down-pipes are fitted with diversion units. A controller includes a rain sensor to detect a rain event whereupon a time delay is imposed for first flush to flush the roof before the valves close the down-pipes. When the tank is full a float is used to operate the controller to open the valves if they are closed or prevent them closing in the case of a new rain event and the tank being already full.

FIELD OF THE INVENTION

THIS INVENTION relates to a water collection system and in particular but not limited to a water collection system for the collection of rainwater from the roof of a dwelling or building.

BACKGROUND TO THE INVENTION

At present rainwater is generally collected from part only of a roof surface and this collected rainwater is delivered into a rainwater storage tank. The rainwater storage tank is generally connected to one or two down-pipes only, thus capturing only a part of the rain which falls on the total roof area. This means there is only a partial yield of rainwater.

It is an object of the present invention to recover a greater proportion of rainfall falling upon any particular roof by utilising more of the roof surface. The present invention may be fitted to a new building structure or retrofitted to existing buildings with only minor modification.

Consequently, it is an object of the present invention in a preferred form to use an existing roof guttering and to control the rainwater that would normally be lost so that water, flows to the tank.

It is an object of another preferred form of the invention to provide a rainwater diversion unit which may be used to easily retrofit an existing building.

A still further object of another preferred form is to provide a first flush of variable duration in order to optimise water quality.

OUTLINE OF THE INVENTION

In one broad aspect the present invention resides in a water collection system where rainwater falls onto a catchment surface and water flows from the catchment surface to respective flow means and then to respective drainage means, diversion means moveable from an open position to a closed position to prevent water from passing down the drainage means so that water is delivered preferentially to a rainwater storage. Preferably, an overflow system is employed whereby excess water may bypass the diversion means and flow to the drainage means. The diversion means may be located in the drainage means or upstream thereof. The overflow system may be located adjacent the drainage means or elsewhere in the system. Preferably, diversion takes place after a predetermined time delay from onset of rain.

Herein, “predetermined time delay from onset of rain” means a time delay added to any inherent delay in the system and is the time delay after verification of rain using a sensor.

In another aspect the present invention resides in a water collection system where rainwater falls onto a catchment surface and water flows from the catchment surface to flow means and then to respective drainage means, at least some of the drainage means comprising diversion means adapted to selectively block flow of water to the drainage means so that it flows to storage unless the system is at capacity. Typically, the system may reach capacity during a rain event in which case the diversion means will cease blocking flow to the drainage means or the system will be at capacity at the onset of a rain event in which case the diversion means will not operate to block flow.

Preferably, the system employs an overflow system whereby excess water may bypass the diversion means and flow to the drainage means. Usually, water flows initially in multiple directions to the separate drainage means and then once the water reaches a certain level water flows in the opposite direction to the storage and at a still further level the overflow system comes into play.

The diversion means may be static or active, in the case of an active diversion means a valve means is preferably used. Where an active diversion means is used a control means is preferably employed to activate the diversion means. The drainage means are typically down-pipes to stormwater. The flow means is typically a gutter surrounding the catchment surface. The storage is typically one or more tanks.

The control means typically includes a rain sensor which activates the system when rain is detected. The system preferably has an inbuilt time delay geared to allow a first flush of water to flush the catchment surface before diversion of later cleaner water to the storage. During this initial period water flows to the stormwater. At the end of the time delay valves block flow to the down-pipes and water flows to the storage.

In case of a heavy downpour, the capacity of the system may be exceeded. The amount of water may exceed the gutter capacity and the capacity of the system to divert all water to the storage, so to prevent gutter spill, the overflow system comes into play. Typically, static overflows project as open ended tubes up into the gutter adjacent each down-pipe. The amount they project determines the level that water reaches in the gutter before the diversion means is bypassed. The height of the overflow above the bottom of the gutter is chosen to ensure sufficient water level in the gutter to exceed the high point of the gutter system due to normal fall requirements. However, the height of the static overflow is selected so that it is high enough for flow over the high point but low enough so that during heavy downpours the gutter does not overflow.

While a static overflow is preferred, gutter overflow may be achieved in many alternative ways. For example the diversion means may be a valve that is controlled by a servo to allow limited flow through the valve to maintain a preset equilibrium in heavy rain events by allowing partial flow thereby effectively providing an overflow through the valve rather than parallel to it. This would be more expensive and would have more maintenance issues but never the less would be one way to implement the invention.

The control means typically operates automatically when the storage is full so that there in no diversion and water flows to stormwater either via the drainage means or via another route. Preferably, when the tank is full the diversion means do not operate or if the storage fills during a rain event the diversion means automatically open upon the storage filling so that water flows to stormwater in the usual way.

Other variations and advantages of the invention will become apparent from the following description of more preferred aspects.

In one preferred form there is provided a water collection system where rainwater falls onto a catchment surface and water flows from the catchment surface in multiple directions to respective flow means and then to respective drainage means, at least some of the drainage means comprising diversion means adapted to prevent water from passing down the drainage means so that water flowing in the system is delivered preferentially to a rainwater storage, and there being an overflow system whereby excess water may bypass the diversion means and flow to the drainage means. Preferably the overflow system comprises an overflow adjacent to the diversion means.

Preferably, the diversion means comprises a valve means.

Preferably, the control means includes a rain sensor which activates the system when rain is detected.

Preferably, the system has an inbuilt time delay geared to allow first flush of water to flush the catchment surface before diversion of later cleaner water to the storage.

Preferably, the system has an inbuilt time delay geared to allow first flush of water for an initial period to flush the catchment surface before diversion of later cleaner water to the storage, during this initial period water flows to the stormwater.

Preferably, the system has an inbuilt time delay geared to allow first flush of water for an initial period to flush the catchment surface before diversion of later cleaner water to the storage, during this initial period water flows to the stormwater, at the end of the time delay valves shut off flow to the down-pipes and water flows to the storage.

Preferably, the system has drainage means in the form of a gutter and down-pipes, an inbuilt time delay geared to allow a first flush of water for an initial period to flush the catchment surface before diversion of later cleaner water to the storage, during this initial period water flows to the stormwater, at the end of the time delay valves shut off flow to the down-pipes and water flows to the storage, overflows project up into the gutter adjacent each down-pipe, the height of the overflows being chosen to ensure sufficient level in the gutter to exceed the highest low point on the gutter due to normal fall requirements to make sure there is flow to the storage but to allow the diversion means to be bypassed to stormwater in heavy downpours.

Preferably, the system further includes control means which operates automatically when the storage is full so that the water is not diverted but flows to stormwater either via the drainage means or via another route.

Preferably, when the storage is full the diversion means do not operate or if the storage fills during a rain event the diversion means automatically opens upon the storage filling.

Preferably, the diversion means comprises a rainwater diversion unit having a housing, an inlet enabling connection of the housing to a gutter at an upstream end of the housing, an outlet enabling connection of the housing to a down-pipe at a downstream end of the housing, an overflow, a valve member movable between inlet open and inlet closed positions and a valve member actuator controllable to operate the valve member, the overflow being so dimensioned and arranged such that when the valve member is in the closed position water flowing in the gutter flows through the overflow when the water level in the gutter reaches the overflow.

In another preferred aspect there is provided a rainwater diversion unit for retrofit to a down-pipe in an existing building to divert rainwater to a storage, the unit having a housing, an inlet enabling connection of the housing to a gutter at an upstream end of the housing, an outlet enabling connection of the housing to a down-pipe at a downstream end of the housing, an overflow, a valve member movable between inlet open and inlet closed positions and a valve member actuator controllable to operate the valve member, the overflow being so dimensioned and arranged such that when the valve member is in the closed position water flowing in the gutter flows through the overflow when the water level in the gutter reaches the overflow.

Preferably, the level of the overflow is between the level of the highest point of the gutter bottom and an upper level of the gutter. Preferably, the inlet and overflow both communicate with the outlet. Preferably, the overflow projects into the gutter though a bottom wall of the gutter and the level of the overflow is set by the distance that the overflow projects into the gutter. Preferably, the overflow is set beside and above the inlet.

In a particular application the invention is applied to a rainwater collection system in a domestic dwelling having a roof catchment with at least two drains to stormwater via guttering, the system having a storage connected to the guttering and there being valve means for diverting rainwater normally flowing down the drains, to the storage. Preferably, the diversion occurs within a predetermined time delay from onset of rain. Preferably, each drain has a rainwater diversion unit between the guttering and the associated drain, each unit having two inlets, the first inlet having an associated valve member so it may be opened and closed while the second inlet is an overflow, the inlets being in flow communication with the associated drain. Preferably, the diversion occurs within a predetermined time delay from onset of rain, the storage having a detector to detect when the storage is full, the detector communicating with control means to automatically cease diversion to the storage during a rain event upon detecting that the storage is full or prevent diversion at the start of a rain event upon detecting that the storage is full.

In an especially preferred form the diversion occurs within a predetermined variable time delay from onset of rain and the storage has a detector to detect when the storage is full, the detector communicating with control means to automatically cease or prevent diversion to the storage upon detecting that the storage is full, the detector comprising a float and the control means having a pneumatic drive communicating with respective valve actuators, the control means being housed above the storage with a mechanical link to the float.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the present invention may be more readily understood and be put into practical effect, reference will now be made to the accompanying drawings which illustrate a preferred embodiment of the present invention and wherein:—

FIGS. 1 and 2 are drawings illustrating aspects of the prior art;

FIG. 3 is a drawing similar to FIG. 1 but illustrating application of the present invention to the same roof structure as illustrated in FIG. 1;

FIG. 4 is a perspective drawing of a typical suburban home fitted out with the present invention;

FIG. 5 is a part cut-away view of a down-pipe diversion unit and tank pipe suited to the present invention;

FIGS. 6 and 7 are views illustrating a down-pipe diversion unit;

FIG. 8 is a block diagram of a typical controller with a compressed air output to air operated valve actuators;

FIG. 9 is a block diagram showing five actuators mounted in parallel;

FIG. 10 illustrates operation of the system in a first flush operation or when there is no diversion and rainwater is flowing to the stormwater and not to the storage tank or if the storage tank is full;

FIG. 11 illustrates operation of the system after first flush is complete and water is being diverted to the rainwater tank; and

FIG. 12 illustrates operation of the system during an overcapacity situation in heavy downpour.

METHOD OF PERFORMANCE

Referring to the drawings and initially to FIG. 1 there is illustrated a prior art setup where a roof 10 of a domestic dwelling has a water tank positioned at 11. In this case the roof is T-shaped having ridges 12 and 13 and during rainfall water flows to the surrounding gutter 14. To collect all water extra tanks are required in this case three tanks in total. Tanks may be located at 11 or at the positions shown in phantom at 15 or 16 in order to use the whole roof catchment but in the case of tank 11 the rain falling on the hatched section 12 of the roof would be all that would be collected in the storage tank 11. The other sections of roof shown would not result in collection of that water over that area and that water would simply flow to stormwater. This is due to the required fall on each section of gutter which must have a high point. Water flows to the tank 11 via a connecting pipe 17 and overflow from the tank is taken to stormwater via pipe 18 connected to down-pipe 19.

FIG. 2 shows a typical prior art tank 11 with the pipes 17 and 18 and a first flush arrangement at 20. The first flush arrangement has a vertical cylinder 21 of a set volume which initially fills lifting the valve float 22 to the top to close off the cylinder so that water then flows to the tank 11. The cylinder empties though a bleed valve at 23. It will be appreciated that the first flush is volumetric and is not variable in any way. Likewise the tank has to be plumbed to the stormwater for overflow and this restricts the possible tank locations in any dwelling. If the first flush is insufficient contaminated water flows to the tank.

The preferred embodiment of the invention is to create a situation where the whole roof area is used for collection and water would flow into the rainwater tank, thus in the present example all down-pipes 19, 24, 25 and 26 would automatically be closed off by suitable valve means during a rain event so that water along the entire length of the guttering 14 would flow to the tank 11. Thus only one tank is needed. Also according to the preferred embodiment, the tank may be located anywhere around the dwelling.

FIG. 3 illustrates the simplicity of the present invention as applied to the same dwelling with roof 10 but in this case there are modified down-pipes 27, 28, 29 and 30 each equipped with respective diversion valve assemblies 31, 32, 33 and 34. The assemblies are water diversion units made at the factory and simply installed as units after part of an existing down-pipe is removed.

Typically, a rain sensor 35 detects the onset of rain and after a pre-determined period of time allowing the roof to flush, diversion valve assemblies 31, 32, 33 and 34 close to divert water from the stormwater. The water initially flows to the down-pipes but as the level rises over any high points it begins to flow to the rainwater tank. In the case of heavy down pour, once the system reaches capacity the system is equipped with overflow means. These are located at each down-pipe adjacent each valve and are part of the diversion unit so that excess water may bypass the closed valves at each location and be directed through the down-pipes to stormwater to prevent gutter overflow.

First flush can be controlled using a variable timer and the entry to the tank pipe being raised above the base of the gutter so the water level in the gutter must rise above the inlet before any water flows to the tank. Thus there is the sequence of first flush set at a duration to optimise the first flush for the desired water quality, valves closed, water level rises in the gutter, water level rises above the level of the tank inlet and water flows to tank, if the water level continues to rise excess flows to stormwater via the overflows or if the tank fills to capacity the valves open. If the tank is already full at onset of rain the valves remain open.

Due to the rain sensor having an inherent delay in sensing rain, the roof will already be subject to flushing before the valves are closed so the minimum flush will be the duration of the inherent latency in the system from onset of rain till activation of the valves without any added delay. In some cases this will be enough, in other cases it will be desirable to extend the duration of the first flush and in the preferred embodiment this is achieved electronically so that duration of the first flush may be selected to optimise water quality. The effectiveness of the flush will depend on many variables including the intensity of the rain at the time, local environmental factors that cause accumulation of contaminants on the roof and the frequency of rain events which will determine the level of the contaminants that have to be flushed. Thus the duration of the first flush should wherever possible be optimised as a trade off between water quality and maximising yield. The following factors will be considered and the flush time set and this may be adjusted as may be required from time to time, the factors being as follows:

-   -   the water quality required or achievable (increase duration of         first flush to improve water quality);     -   local contamination levels (increase duration of first flush in         high contamination areas);     -   anticipated frequency of rain events (increase duration of first         flush in low frequency locations).

In the case where the duration is set manually it is largely a trial an error setting although the water may be tested at different flush settings. An alternative is to provide dynamic control by monitoring flow rates and making the flush time variable and dynamically adjust the first flush accordingly. However in most cases the additional time added on to the inherent time delay would range from 2 to 5 minutes.

An example of the modified arrangement where a diversion unit has been fitted is illustrated in FIG. 4. Like numerals illustrate like features. The arrangement at the down-pipe 27 and tank pipe 17 is illustrated in more detail in FIGS. 5, 6 and 7. The valve assembly 31 comprises a box 36 with the down-pipe 27 fitted to an opening 37 in bottom 38 of the box 36. The gutter 14 has two side-by-side openings 39 and 40, the opening 40 has an upstanding wall 41 while the opening 39 has a valve plate 42 hinged to the front edge at 43. A pneumatic actuator 44 is used to move the valve plate 42 to the closed position shown in FIGS. 5, 6 and 7. The open position is shown in phantom. When the valve is closed, the opening 40 and the upstanding wall 41 serve as an overflow back to the stormwater via the box 36. The tank pipe 17 also has an opening 45 with an upstanding wall 46 which has its upper edge 47 set lower than the upper edge 48 of the wall 41 of the overflow. Thus water will continue to flow to the tank as long as the tank is not full.

Referring now to FIGS. 8 and 9 the controller will be described in more detail. The controller is shown in a box 49 on top of the tank 11 with a solar panel 50 used to trickle charge a battery 51. Air actuators 52-55 (or as many as there are down-pipes) are vented through an air relief valve 56 operated by a float 57 and float arm 58 when the water tank is full. This opens the diversion valves and water flows to the stormwater. Air is delivered to the actuators along line 59 via an air/electric switch 60 from compressor 61. The compressor is switched on after a variable timer relay 62 is closed, with the timer being set to the desired time delay for the desired first flush. If the event of system failure relay 63 switches the system off and fault indicator light 64 lights.

FIGS. 10-12 illustrate operation of the system in various circumstances. FIG. 10 illustrates the first flush, FIG. 11 illustrates diversion to the tank and FIG. 12 illustrates overflow. In FIG. 12 water may still flow to the tank but once the tank is full air will vent from the actuators and all valve plates will move to the inlet open position.

When a rain event occurs following first flush the valves close and rainwater bypasses the down-pipes and flows along the gutter where it is collected in the rainwater storage tank. The valve assemblies may be easily made as boxed units simply inserted into existing down-pipes by removing a section of down-pipe and cutting a hole in the gutter for the overflow. These are placed at corresponding down-pipes where ever they occur on a roof so that water that would normally pass down the down-pipes is diverted to the storage tank. In the case of heavy rain, the arrangement at the down-pipes is that the wall 41 will project into the gutter at a height “H” marginally higher than the highest point related to the fall of the gutter to that particular down-pipe to ensure that there is sufficient depth so that water passes above the highest point from the far side. In the case of heavy rainfall when the water level gets above the height H water flows through the over flow in the direction of the arrows as shown in FIG. 12 so that the valve is bypassed to ensure that the gutters 14 do not over flow.

Whilst the above has been given by way of illustrative example of the present invention many variations and modifications thereto will be apparent to those skilled in the art without departing from the broad ambit and scope of the invention as set out in the appended claims. 

1. A water collection system where rainwater falls onto a catchment surface and water flows from the catchment surface to respective flow means and then to respective drainage means, diversion means moveable from an open position to a closed position to prevent water from passing down the drainage means so that water is delivered preferentially to a rainwater storage, and an overflow system whereby excess water may bypass the diversion means and flow to the drainage means.
 2. A water collection system according to claim 1 wherein the diversion means comprises a valve assembly.
 3. A water collection system according to claim 1 further including control means and wherein the control means includes a rain sensor which activates the system to move the diversion means to the closed position when rain is detected.
 4. A water collection system according to claim 1 wherein the system has an inbuilt time delay geared to allow first flush of water to flush the catchment surface before diversion of later cleaner water to the storage.
 5. A water collection system according to claim 1 wherein the system has an inherent time delay geared to allow first flush of water for an initial period to flush the catchment surface before diversion of later cleaner water to the storage, during this initial period water flows to the stormwater.
 6. A water collection system according to claim 1 wherein the diversion means comprises valves and the system has a variable time delay geared to allow first flush of water for an initial period to flush the catchment surface before diversion of later cleaner water to the storage, during this initial period water flows to the stormwater, at the end of the time delay the valves shut off the down-pipes and water flows to the storage.
 7. A water collection system according to claim 1 wherein the system has flow means in the form of a gutter and drainage means in the form of down-pipes, a time delay geared to allow a first flush of water for an initial period to flush the catchment surface before diversion of later cleaner water to the storage, during this initial period water flows to the stormwater, at the end of the time delay the diversion means shuts off flow to the down-pipes and water flows to the storage, overflows project up into the gutter adjacent each down-pipe, the height of the over low being chosen to ensure sufficient level in the gutter for flow to the storage but to allow the diversion means to be bypassed to stormwater in heavy downpours.
 8. A water collection system according to claim 1 further including control means which operates automatically when the storage is full so that the water flows to stormwater either via the drainage means or via another route.
 9. A water collection system according to claim 1 wherein, when the storage is full the diversion means do not operate or if the storage fills during a rain event the diversion means automatically opens upon the storage filling.
 10. A water collection system according to claim 1 wherein a variable time delay is used to set the duration of first flush.
 11. A water collection system according to claim 1 wherein, the diversion means comprises a rainwater diversion unit having a housing, an inlet enabling connection of the housing to a gutter at an upstream end of the housing, an outlet enabling connection of the housing to a down-pipe at a downstream end of the housing, an overflow, a valve member movable between inlet open and inlet closed positions and a valve member actuator controllable to operate the valve member, the overflow being so dimensioned and arranged such that when the valve member is in the closed position water flowing in the gutter flows through the overflow when the water level in the gutter reaches the overflow.
 12. A rainwater diversion unit having a housing, an inlet enabling connection of the housing to a gutter at an upstream end of the housing, an outlet enabling connection of the housing to a down-pipe at a downstream end of the housing, an overflow, a valve member movable between inlet open and inlet closed positions and a valve member actuator controllable to operate the valve member, the overflow being so dimensioned and arranged such that when the valve member is in the closed position water flowing in the gutter flows through the overflow when the water level in the gutter reaches the overflow.
 13. A rainwater diversion unit according to claim 12 wherein the level of the overflow is between the level of the highest point of the gutter bottom and an upper level of the gutter.
 14. A rainwater diversion unit according to claim 12 wherein the inlet and overflow both communicate with the outlet.
 15. A rainwater diversion unit according to claim 12 wherein the overflow projects into the gutter though a bottom wall of the gutter and its level is set by the distance that the overflow projects into the gutter.
 16. A rainwater diversion unit according to claim 12 wherein the overflow is set above the inlet.
 17. A rainwater collection system in a building having a roof catchment with at least two drains to stormwater via guttering, the system having a storage receiving water flowing in the guttering and there being valve means operable by a controller to divert rainwater normally flowing down the drains, to the storage.
 18. A rainwater collection system according to claim 17, the diversion occurring within a predetermined time delay from onset of rain.
 19. A rainwater collection system according to claim 17 wherein each drain has a rainwater diversion unit between the guttering and the associated drain, each unit having two inlets, the first inlet having an associated valve member so it may be opened and closed while the second inlet is an overflow, the inlets being in flow communication with the associated drain.
 20. A rainwater collection system according to claim 17, the diversion occurring within a predetermined time delay from onset of rain and the storage having a detector to detect when the storage is full, the detector communicating with a controller to automatically cease or prevent diversion to the storage upon detecting that the storage is full.
 21. A rainwater collection system according to claim 17 wherein the storage has a detector to detect when the storage is full, the detector communicating with a controller to automatically cease diversion to the storage upon detecting that the storage is full.
 22. A rainwater collection system according to claim 17, the diversion occurring within a predetermined time delay from onset of rain and the storage having a detector to detect when the storage is full, the detector communicating with a controller to automatically cease or prevent diversion to the storage upon detecting that the storage is full, the detector comprising a float and the controller having a pneumatic drive communicating with respective valve actuators, the control means being housed adjacent the storage with a mechanical link to the float.
 23. A rainwater collection system according to claim 17 wherein water initially flows in the direction of the respective drains and then flows to the storage tank, there being an overflow operable to prevent gutter spill in case of heavy downpours. 